3 manual tuning, 1 explanation of servo gain – Yaskawa Sigma II Series DC Power Input SGMAJ User Manual
Page 262

9.3 Manual Tuning
9-11
9
9.3 Manual Tuning
9.3.1 Explanation of Servo Gain
The block diagram for position control is as follows:
To adjust the servo gain manually, understand the configuration and characteristics of the SERVOPACK and 
adjust the servo gain parameters one by one. If one parameter is changed, it is almost always necessary to adjust 
the other parameters. It will also be necessary to make preparations such as setting up a measuring instrument to 
monitor the output waveform from the analog monitor.
The SERVOPACK has three feedback loops (i.e., position loop, speed loop, and current loop). The innermost 
loop must have the highest response and the middle loop must have higher response than the outermost. If this 
principle is not followed, it will result in vibration or responsiveness decreases.
The SERVOPACK is designed to ensure that the current loop has good response performance. The user need to 
adjust only position loop gain and speed loop gain.
Encoder
Position control loop (SGDJ-P)
Speed control loop (SGDJ-S)
Speed
Speed pattern
Time
Move
reference
Error
counter
Position
loop
gain
Kp
Speed 
control
section
Kv
Ti
+
-
Current 
control 
section
Electric 
power 
converting
Servomotor
M
PG
Position loop
SERVOPACK
Host controller
(provided by user)
Kp Position Loop Gain (Pn102
Kv Speed Loop Gain Pn100
Ti
Speed Loop Integral Time
Constant (Pn101)
Tf Torque Reference Filter Time 
 Constant (Pn401)
+
-
+
-
Speed
reference
Speed loop
Current loop
Tf
